Kuan-Cheng Lu
;
Chetan Awasthi
;
Ta-Wei Chiu
;
S. S. Islam
;
Kimitoshi Kono
;
Kazuhito Tsukagoshi
;
Wen-Bin Jian
説明:
(abstract)Two-dimensional transition metal dichalcogenides (2D TMDs) have emerged as promising candidates for next-generation electronic devices in the post-Moore’s Law era. However, the high-power densities of these devices lead to substantial heat generation, highlighting the importance of thermoelectric generators for waste heat recovery. Among 2D TMDs, ultrathin MoS2 has shown considerable potential for applications in both nanoscale transistors and thermoelectric generators. Nevertheless, the correlation between its electrical transport and thermoelectric properties remains insufficiently understood and warrants further investigation. To address this, we fabricated thermoelectric field-effect transistors using MoS2 flakes (1 to 39 layers). We measured electrical and thermoelectric properties from 80 K to 600 K, analyzing transport behaviors using Mott's hopping transport, thermal activation, and phonon scattering theories. We especially studied their dependence on the carriers’ concentration. This analysis allowed us to extract the universal Boltzmann constant k_B and the electron’s effective mass m^*. Our findings indicate that thermoelectric performances achieve the optimum state for MoS2 flakes with thicknesses less than 20 layers, where the high-voltage output and maximum energy conversion efficiency occur at 15–20 and 1-5 layers, respectively. Notably, we present the electron's effective mass as a function of flake thickness. We identified an extrinsic effect of memory steps, caused by trapped charge release above 450 K, which significantly enhances electrical and thermoelectric properties.
権利情報:
キーワード: Two-Dimensional Semiconductors, Seebeck Coefficient, MoS2, Mott’s Hopping Transport
刊行年月日: 2026-03-01
出版者: AIP Publishing
掲載誌:
研究助成金:
原稿種別: 査読前原稿 (Author's original)
MDR DOI: https://doi.org/10.48505/nims.6121
公開URL: https://doi.org/10.1063/5.0291091
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更新時刻: 2026-01-14 10:42:17 +0900
MDRでの公開時刻: 2026-01-14 12:20:08 +0900